I added a layer of metal to a cuff fixing with 5 rivets, one on each
corner and a centre rivet. I then formed on a bracelet mandrel. In
doing this, the riveted layer appears to 'stretch' during the
shaping process causing 3 of the rivets to pull out. How can I
overcome this problem? Riveting after it has been formed doesn't
seem feasible as it's too difficult to hammer in the curved areas.
Appreciate any advice, thanks.
I do a lot of riveting and have found that after doing the riveting
if you can anneal the riveted area then you can bend and form the
piece without popping the rivets. The rivets become very work
hardened. I have been able to bend, shape and form pieces that are
two, three and sometimes four layers joined together with rivets
without problems. I once made a bracelet of two 18 gauge pieces of
metal joined to a 16 gauge piece, very heavy and big for a big guy
and was able to shape it on a mandrel without problems after
annealing. If for some reason you can't anneal it then at the moment
I'm at a loss for a solution.
Happy to help, BUT need to know
1. Cuff metal, width and thickness
2. top metal, width and thickness, if annealed
3. rivet material and dia
4. Wether rivet pulled out of top or bottom metal.
any pictures? I made lots using 3 layers, base s/steel 30/1000 1.25
wide middle 25/1000 70/30 brass 3/4 wide top 25/1000 copper 1/4 wide.
soldered as in siver brazing just the end 1/2in.
formed around mandrel no problems.
A good seller.
await your eply
I would make a tool that would fit into the curved area kinda like a
bent ring stamp but larger.
Panama Bay Jewelers
Thank you so much for your reply Jima. Sometimes I really fail with
logical thinking, it didn't occur to me that it needed annealing
Ted - I used a 1.2mm aluminium base and riveted a 0.7mm copper piece
slightly smaller than the base. The overall cuff measured 40mm wide
by 150mm long. Both annealed before riveting, but as Jima has
pointed out, the problem may well be not annealing again before
shaping. The rivets pulled out both top and bottom on the edges.
Vernon - yes that is another good idea. You are suggesting to have a
curved hammering tool to enable riveting after shaping, right?
A great help, many thanks!
Lorraine- Regardless of annealing or not, the holes for the rivets
will stretch out into ovals if bent thus compromising your rivets.
Always shape before you drill, rivet or solder two pieces together.
I often resort to using my ball punches in a vise to support rivets
underneath in a formed piece. A ring mandrel or a bracelet mandrel
in a vise would work as well.
Have fun and make lots of jewelry.
Lorraine, your reply is a useful but small step forward.
However you didnt give any rivet details.
now you need to go to Ebay UK and type in model engineering rivets.
Thats the size ie mostly 1/16in dia you should be using with the
round head on the copper sheet. tho they will be hard and need
annealing if your riveting to ali. Copper harder than ali? get it?
use stainless steel as a backing, a much better option..
This needs to be at least 1.5 mm thick. Less is not thick enough.
this can be counter sunk 120deg by 3mm wide so the rivet is flush
with the inside.
Also google, for aircraft riveting specifications. as your using
industrial joining techniques in jewellery you need to know what
size rivets are used on what thickness sheet. Know how thats been
around since the 1930's.
Next you need to think of the tension load on the copper sheet
pulling on the rivet in shear. The no of rivets you need have to give
more strength than the load stretching the copper sheet when bent
around the cuff mandrel. Just simple engineering really. its all been
done before. If you cant hide a joining/ assembly technique, turn it
into part of the design.
As Ive said before do your research and run lots of trials your
learn so much that way. Once youve got the materials right and the
technique right, youll be making them by the dozen in all the
different sizes . Then have lots of sales.
do sign and date them as well with hand stamps.
Youll owe me one for all this inside know how on profit making!!.